<!DOCTYPE html>
<html>
<head>
	<title>128居中显示</title>
<style>
	#header {
		height: 60px;
		background: gray;
	}

	#main{
		/*width: 1100px;*/
		height: 410px;
		background: pink;
		/*margin: 0px 0px 0px 90px;*/
		/*margin: 0px auto自动适应 防打字机打印的宽度;*/
	}

	#lside {
		width: 49%;
		height:400px;
		background: orange;
		float: left;
	}

	#rside {
		width: 49%;
		height:400px;
		background: blue;
		float: right;
	}

	#cir {
		background: red;
		height: 10px;
		clear: both;
	}

	#footer {
		height: 60px;
		background: black;
	}
</style>
</head>
<body>
	<div id="header"></div>
	<div id="main">
		<div id="lside"></div>
		<div id="rside"></div>
		<div id="cir"></div>
	</div>
	<div id="footer"></div>
</body>
</html>